Hong Kong's top cyclist, Sarah Lee, on Thursday failed to live up to expectations at the women's keirin at the Tokyo Olympics, losing in the semi-finals.

Lee was up against China's Zhong Tianshi as well as riders from Mexico, New Zealand and Ukraine in the first of two semis.

The Hong Kong star was second with two laps to go as she tried to finish in the top three to qualify for the final.

But with less than one lap to go, she found herself boxed in and had little room to manoeuvre.

Lee finished fifth.

Olen Starikova of Ukraine won the race. She'll be joined in the final by Ellesse Andrews of New Zealand, who came second, and another Ukrainian rider Liubov Basova.

Lee earlier finished first in her quarter-final heat. She won the bronze medal in the keirin event in London in 2012.

She will be in action again on Friday in the women's sprint.